On production specific domains can not be resolved

[alexander-schranz]

I have a IONOS and google cloud server and some A records fail to resolve the DNS_A + DNS_MX part:

php -r 'require_once("vendor/autoload.php"); $dnsCheckValidation = new \Egulias\EmailValidator\Validation\DNSCheckValidation(); var_dump($dnsCheckValidation->isValid("somemail@adif.es", new \Egulias\EmailValidator\EmailLexer())); var_dump($dnsCheckValidation->getError());'

Locally all works like expected.

If I change todo only a MX Lookup and not a A lookup all works like expected:

-        $dnsRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_A + DNS_MX);
+        $dnsRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_MX);

So maybe change to something like:

        $dnsRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_MX);

        $dnsRecords = [];
        if (! $dnsRecordsResult->withError()) {
            $dnsRecords = $dnsRecordsResult->getRecords();
        }

        $dnsRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_A);

        if (! $dnsRecordsResult->withError()) {
            $dnsRecords = array_merge($dnsRecords, $dnsRecordsResult->getRecords());
        }

        // Combined check for A+MX+AAAA can fail with SERVFAIL, even in the presence of valid A/MX records
        $aaaaRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_AAAA);

        if (! $aaaaRecordsResult->withError()) {
            $dnsRecords = array_merge($dnsRecords, $aaaaRecordsResult->getRecords());
        }

Think this is similar to @crishoj #376

[alexander-schranz]

Not sure when we should then throw the UnableToGetDNSRecord exception, only if all lookup fails?

        $dnsRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_MX);

        $dnsRecords = [];
        if (! $dnsRecordsResult->withError()) {
            $dnsRecords = $dnsRecordsResult->getRecords();
        }

        $dnsRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_A);

        if (! $dnsRecordsResult->withError()) {
            $dnsRecords = array_merge($dnsRecords, $dnsRecordsResult->getRecords());
        }

        // Combined check for A+MX+AAAA can fail with SERVFAIL, even in the presence of valid A/MX records
        $aaaaRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_AAAA);

        if (! $aaaaRecordsResult->withError()) {
            $dnsRecords = array_merge($dnsRecords, $aaaaRecordsResult->getRecords());
        }

        if (count($dnsRecords) === 0) {
            $this->error = new InvalidEmail(new UnableToGetDNSRecord(), '');

            return false;
        }

@egulias what do you think?

[alexander-schranz]

PS: Tried today a Hetzner Cloud server which has the same issue. I also tried directly the PHP:

php -r 'var_dump(dns_get_record("adif.es", DNS_A + DNS_MX));'

And it fails. Did found out the used DNS and tried dig command which ends in:

dig @185.12.64.2 +short A adif.es

Goes into ;; connection timed out; no servers could be reache

while over google it not errors just return nothing what is expected as only a MX record exists:

dig @8.8.8.8 +short A adif.es

[alexander-schranz]

Open a PR: #410

[egulias]

Many thanks for the investigation @alexander-schranz and the PR. Well done!